Well, it hasn't happened to me but there's a whole thread over on viahardware.com that's full of people that have, so I have to believe it's real.
This weekend I put back my spare HDD on the secondary IDE channel. I was reminded of why I removed it in the first place (noise!). I then ran transfer tests using a 500M file under ME, W2K, and Linux, all while playing a 1-hour mp3 using WinAmp or the Real player through to my SB Live! In other words, I was laughing at death! I had to use a very large file because the huge amount of memory on my system was skewing the results, since smaller files would just get cached in RAM.
So, the result is that after 4-5 transfer attempts under each OS, checksumming the file each time, there were no errors. I did get some dropouts in the audio when the disks were heavily loaded. The dropouts are of 0.5-second duration and were expected. Actually I was pleasantly surprised that they occurred only on Linux, though I am able to reproduce them under ME and W2K if I transfer to a slower device.
Both drives were masters on each of the two IDE channels. Under all three OSes, as far as I can tell from the device manager, both drives were running in UDMA mode. The main drive is a 40G ATA100 Fireball, but the spare drive is only ATA66 - not sure if this would make much difference or not.
My CD drive, where I do a lot of the backups, is not running in DMA mode. Given the suspected problems, I may just leave it in PIO mode -- I don't need speed from it, just reliability (my games are all on the hard drive).
So, I don't know why I'm so lucky. I have the exact parts that everyone's b|tching about, and no problem since installing the 1004 BIOS and the VIA 4-in-1. Your mileage may vary.
Doug